湿沉淀对采汞地区山地土壤中汞的影响

There is abundance of Mercury mine resurces in the Fanjinshan Mountain,Mining mercury has a long history there,The concentration of geseous Hg produced in smelting He reaches 20-50mg/m^3 in the tail gas.Because mercury element is an easily transferring microelement,the paper talks about the effect of mercury in Hg mining in Guizhou Province on alpine soil,analyses Hg content in alpine soil at 2000 m of relative elevation in the Hg mining area,and explores for causes of the Hg pollution.     

土-水体系中Hg的垂直迁移

Hg vertical transference in soil-water system w as studied by analyzing Hg vertical distribution in soil column after adding Hg and one of the two leacheates, deionized water or acid rain, into soil column. The results indicated that Hg was hardly transferable in purple soil. About 86% ~ 88% of the total soil Hg was distributed in the top layer (0~2 cm) and no Hg was detected in the leakage when the purple soil column was leached by deionized water and simulated acid rain. But Hg was more movable in yellow soil with only about 20%~22% of the total soil Hg distributed in the top layer (0~2 cm), and about 17%~25% washed out from the soil column by deionized water and simulated acid rain. Increment in soil bulk density could reduce Hg leaching, thus the more the Hg kept in soil, the less the Hg leached into underground water. Deionized water and acid rain almost played the same role in leaching Hg. Bentonite was most efficient in preventing Hg from vertical transferring in the soil column.     

14C标记秸秆碳素在老成土和变性土中的转化

Hg vertial transference in soil-water system was studied by analyzing Hg vertical ditribution in soil column after adding Hg and one of the two leacheates,deionzied water or acid rain,into soil column.The results indicated that Hg was hardly transferable in puple soil.About 86%-88% of the total soil Hg was distributed in the top layer (0-2cm) and to Hg was detected in the leakage when the purple soil column was leached by deionized water and simulated acid rain.But Hg was more movalbe in yellow soil with only about 20%-22% of the total soil Hg distributed in the top layer (0-2cm),and about 17%-25% washed out from the soil column by deionized water and simulted acid rain,Incremant in soil bulk density colud reduce Hg leaching,thus the more the Hg kept in soil,the less the Hg leached into underground water,Deionized water and acid rain almost played the same role in leaching Hg.Bentioint was most effecient in preventing Hg from vertcal transferring in the soil coulumn.     

土壤硼的电化学特征及解吸动力学

Effects of humus fractions (fulvic acid,brown humic acid and grey humic acid) on the leachability and transferring activity of five types of mineral-bound Hg were investigated.Under the acid leaching condition;fulvic acid could promote leachability and vertical transference of all the mineral-bound Hg.Brown humicacid could retard the leaching and trasferring processes of CaCO30-Hg,Fe2O3-Hg,MnO2-Hg and kaolinite Hg but not bentonite-Hg.Grey humic acid could greatly enhance residing ability of the mineral-bound Hg in the soil colum and restrain them from vertical transferring.The effect of humus on leachability and transferring activity on the mineral-bound Hg was closely related to its ability to convert the mineral-bound Hg into orgainc-bound form and the transferbility of the latter in the soil column.The characteristics of the mineral-bound Hg in speciation were the internal factors that determined the extent and rate of the influence of the humus.     

陇海铁路郑州—圃田段铁路旁土壤重金属污染

The pollution status and horizontal distribution of heavy metals (Ni, Pb, Cr, Zn, Cu, and Cd) in the soil on railroad side along the Zhengzhou-Putian section of Longxi-Haizhou Railroad were studied by collecting soil samples along a sampling section perpendicular to the railroad at the distances of 0, 10, 20, 30, 50, 100, 200, 300, and 500 m from the railroad edge. The concentrations of heavy metals in the sampling soils were higher than those of the control site. The concentrations of Pb, Zn, and Cd were found to be the highest in the soils at the railroad edge, and then decreased with increasing distance from the railroad. The highest concentrations of Ni, Cr, and Cu in soils were located at about 10-30 m from the railroad. Compared with the single factor pollution index (SFPI) of heavy metals calculated for the control site, the average SFPI from the sampling sites decreased in the order of Cr > Cd > Pb > Zn > Ni > Cu. There were notable negative correlations between the integral pollution index (IPI) of soil heavy metals at all sampling sites and the distances from the railroad. According to three IPIs calculated from the background values of heavy metals in och-aquic Cambisols, the heavy metal concentrations in the control soil, and the 2nd levels for soil heavy metals in GB15618-1995, the study area could be divided, based on the distances from the railroad, into four pollution zones: heavy pollution zone (0-10 m), medium pollution zone (10-50 m), slight pollution zone (50-100 m), and warning zone (100-500 m), respectively.     

基于模糊逻辑的北京城市边缘区土壤重金属污染空间预测

Fuzzy classification combined with spatial prediction was used to assess the state of soil pollution in the peri-urban Beijing area. Total concentrations of As, Cr, Cd, Hg, and Pb were determined in 220 topsoil samples （0-20 cm） collected using a grid design in a study area of 2 600 kin2. Heavy metal concentrations were grouped into three classes according to the optimum number of classes and fuzziness exponent using the fuzzy comean （FCM） algorithm. Membership values were interpolated using ordinary kriging. The polluted soils of the study area induced by the measured heavy metals were concentrated in the northwest corner and eastern part, especially the southeastern part close to the urban zone, whereas the soils free of pollution were mainly distributed in the southwestern part. The soils with potential risk of heavy metal pollution were located in isolated spots mainly in the northern part and southeastern corner of the study region. The FCM algorithm combined with geostatistical techniques, as compared to conventional single geostatistical kriging methods, could produce a prediction with a quantitative uncertainty evaluation and higher reliability. Successful prediction of soil pollution achieved with FCM algorithm in this study indicated that fuzzy set theory had great potential for use in other areas of soil science.     

麦根酸的分泌及其对土壤中铁的有效性的影响

Large amounts of phytosiderophore are detected from both the solution and the rhizosphere soil when cereal crops are under Fe deficiency stress.The extension of phytosiderophore in the rhizosphere soil is found only within 1 mm apart from the root surface.The rate of phytosiderophore secretion is negatively related to chlorophyll content in young leaves and positively related to the Fe-solubilizing capacity.Results from in vitro experiments whow 10 μmoles mugineic acid can dissolve 501 μg Fe from iron hydroxide and 146 ug from strengite.Thus,phytosiderophore can considerably enhance the soil iron availability by increasing the solubility of amorphous iron hydroxide and iron phosphate,and active Fe is consequently accumulated in the plant rhizosphere,43% higher than in the bulk soils There is evidence to support that mugineic acid chelates with Fe%3 at a rate of 1:1 in the acid condition.In addition,we observe mugineic acid has certain effects on mobilization of P as well as Fe by dissolving the insoluble iron phosphate,And phytosiderophore seems to be an effective remedy for the chlorosis of dicotyledonous plants.     

洞庭湖地区红土微量与稀土元素地球化学特征及其环境意义

Trace element (TE) and rare earth element (REE) contents in red soils from the Dongting Lake area of China were determined to understanding the provenance and weathering characteristics of the red soils. The results showed similar REE distribution patterns among red soils from the Dongting Lake area, Xiashu loess from Zhenjiang, loess and the Pliocene red soil from the Loess Plateau. These patterns implied a similar provenance from dust-storms, except for red soil R5 which formed by bedrock weathering and had significant light REE (LREE) enrichment and heavy REE (HREE) depletion due to longer weathering periods and higher intensity of weathering. Trace element, especially the Rb/Sr and Li/Ba ratios, and REE, especially the LREE/HREE ratio and δEu could trace weathering intensity. Higher Rb/Sr, Li/Ba, and LREE/ HREE ratios and negative Eu anomalies were present in the red soil from the Dongting Lake area. The weathering intensity was in the decreasing order of R5 in the Dongting Lake area > red soil from the Dongting Lake area (including reticulate red soil, weak reticulate red soil, and homogeneous red soil formed by dust storms) > Xiashu loess from Zhenjiang > Loess-paleosol and Pliocene red soil from the Loess Plateau. Variations in the TE and REE contents of soil could be effectively used to study the provenance and the weathering intensity.     

不同种植模式和土壤类型条件下土壤健康的定量评价

Soil health assessment is an important step toward understanding the potential effects of agricultural practices on crop yield, quality and human health. The objectives of this study were to select a minimum data set for soil health evaluation from the physical, chemical and biological properties and environmental pollution characteristics of agricultural soil and to develop a soil health diagnosis model for determining the soil health status under different planting patterns and soil types in Chongming Island of Shanghai, China. The results showed that the majority of the farmland soils in Chongming Island were in poor soil health condition, accounting for 48.9% of the survey samples, followed by the medium healthy soil, accounting for 32.2% of the survey samples and mainly distributed in the central and mid-eastern regions of the island. The indicators of pH, total organic carbon, microbial biomass carbon and Cd exerted less influence on soil health, while the soil salinization and nitrate accumulation under a greenhouse cropping pattern and phosphate fertilizer shortage in the paddy field had limited the development of soil health. Dichlorodiphenyltrichloroethanes, hexachlorocyclohexanes and Hg contributed less to soil health index (SHI) and showed no significant difference among paddy field, greenhouse and open-air vegetable/watermelon fields. The difference of the SHI of the three soil types was significant at P = 0.05. The paddy soil had the highest SHI values, followed by the gray alluvial soil, and the coastal saline soil was in a poor soil health condition, indicating a need to plant some salt-tolerant crops to effectively improve soil quality.     

Incorporation of source contributions to improve the accuracy of soil heavy metal mapping using small sample sizes at a county scale

Estimating heavy metal(HM) distribution with high precision is the key to effectively preventing Chinese medicinal plants from being polluted by the native soil. A total of 44 surface soil samples were gathered to detect the concentrations of eight HMs(As, Hg, Cu, Cr, Ni, Zn, Pb, and Cd) in the herb growing area of Luanping County, northeastern Hebei Province, China. An absolute principal component score-multiple linear regression(APCS-MLR) model was used to quantify pollution source contributio...     

三峡库区消落区土壤重金属污染调查与评价

通过对三峡重庆库区16个区县，183个土壤样品的分析，表明三峡库区消落区土壤重金属含虽均达到国家土壤环境标准3级以上。其中Cu含量范围为10.7～80.2mg／kg，均值为37.0mg／kg；Pb含量范围为14.6～51.8mg／kg，均值为29.3mg／kg；Zn含量范围为47.5～93.3mg／kg，均值为72.7mg／kg；Cd含量范围为0.081～0.864mg／kg，均值为0.321mg／kg；Hg含量范围为0.032～0.204mg／kg，均值为0.059mg／kg；As含量范围为4.63～12.7mg／kg，均值为8.65mg／kg。Cu、Cd之间存在极显著正相关关系，其余各重金属之间相关性不明显，pH值对重金属含量的影响不大。三峡库区消落区土壤主要受Cd、Cu污染。通过系统聚类分析，土壤重金属有明显的地域分布，即水库上游区、中游区和下游区。     

不同污染区土壤汞的分布特征及变化规律

为揭示不同污染区重金属汞在土壤中的存在形态及分布特征,选取万山汞矿区、大龙燃煤电厂区为研究区域,以无污染区花溪区为对照,选择优化的Tessier连续化学浸提法进行汞的形态分析。结果表明:万山汞矿区与大龙燃煤电厂的土壤总汞平均值分别为22.7 mg/kg和0.648 mg/kg,均超过我国土壤环境质量二级标准(0.5 mg/kg),无污染对照区土壤总汞平均为0.179 mg/kg。在水平方向上,万山汞矿区靠近污染源的土壤汞含量相对较高,随着距离的增加而下降;大龙燃煤电厂区土壤汞在距燃煤电厂2.5 km范围内呈现先减小后增大的趋势。汞矿区土壤汞主要以残渣态(66.6%)为主,其次为有机结合态(30.0%);燃煤电厂则主要以有机结合态(75.7%)为主,其次为残渣态(17.46%);无污染区主要以残渣态(59.1%)为主,其次为有机结合态(28.9%)。内梅罗污染综合指数显示,万山汞矿区的土壤污染指数为107,为重度污染,这与污染源强度大有关,2004—2017年,总汞含量呈下降趋势;大龙燃煤电厂土壤污染指数为1.57,为轻度污染,同时土壤汞以有机结合态为主,潜在生物有效性相对较高,有一定的环境生态风险。     

南宁市蔬菜基地土壤重金属含量及评价

通过调查和采样分析结果表明,南宁市蔬菜基地土壤重金属平均含量分别为Cd 0.33 mg/kg、Hg 0.15 mg/kg、As 27.7 mg/kg、Pb 46.7 mg/kg、Cr 133 mg/kg。部分蔬菜基地土壤受到不同程度重金属污染,主要污染物为Cd,其平均单项污染指数为1.10。全市平均综合污染指数为0.91。     

黔产山银花及其产地土壤重金属含量分析与评价

[目的]探明黔产山银花及其产地土壤重金属污染特征,为山银花品质保障、产地土壤重金属防控及规范化种植提供指导。[方法]以贵州山银花及其产地土壤为供试样品,采用ICP-MS测定重金属铜(Cu)、砷(As)、铅(Pb)、镉(Cd)、汞(Hg)、铬(Cr)的含量,采用单因子指数法和内梅罗综合指数法进行分析评价,对黔产山银花及土壤重金属污染水平进行探讨。[结果]结果表明:土壤中6种重金属As,Pb,Cd,Cr,Hg和Cu平均含量分别为9.79,14.30,0.10,19.89,0.12和3.81mg/kg,均未超标;根区与非根区土壤的重金属综合污染指数分别为0.46和0.83,污染等级分别处于安全和警戒线。山银花中Cr,As,Cd,Pb,Cu平均含量分别为5.19,0.16,1.87,0.39和6.86mg/kg,Hg未检出;Hg,As,Pb,Cu未超标,而Cd远超出限量值,超标率为100%,山银花对Cd中具有很强的富集效应。[结论]研究区土壤环境质量总体适宜山银花种植。     

新疆准东煤田土壤重金属来源分析及风险评价

为研究准东矿区土壤重金属来源及生态风险,分析了阜康市至准东矿区中间的3个缓冲区共27个土壤样方的As,Hg,Pb,Cr,Cu,Zn元素重金属含量状况,并利用因子分析、污染指数法、地累积指数法和潜在生态风险指数法对各缓冲区土壤重金属进行了污染来源及风险分析。结果表明:除Cr的总体平均值高于新疆土壤背景值外,其余重金属含量均低于背景值。基于土壤重金属空间分布图显示,除Cu,Hg含量高值分布于C区域土壤外,其余重金属高值均出现在准东矿区(A区域)附近土壤,3个区域各重金属所占比例基本一致,距离矿区越远,变异系数呈减少趋势;污染源分析可知,准东矿区89.3%的Hg来源于煤炭燃烧,40.1%的Pb来源于交通运输,19.65%的As来源于大气降尘,Cu和Cr的主要来源为煤尘,其贡献率分别为60.23%和81.57%,其中29.7%的Cu来源于土壤母质,75.1%的Zn来源于土壤母质;基于污染指数法、地累积指数法和潜在生态危害指数法对不同缓冲区土壤污染风险进行了评价,得出土壤整体呈轻度-中度污染水平,距离矿区越远重金属污染状况越轻。As,Hg,Pb和Cr元素生态风险均呈现缓冲区区域A区域B区域C的趋势,距离矿区越远,生态风险越低。潜在生态风险指数与重金属单因子生态风险的大小顺序一致。     

遵义东南部地区农业土壤重金属分布特征及风险评价

对贵州省遵义东南部地区农业土壤重金属As、Pb、Cd、Cr、Hg污染现状进行调查和分析,结果表明,该地区重金属平均含量分别为:As 11.39mg/kg,Pb 38.75mg/kg,Cd 0.34mg/kg,Cr 40.45mg/kg,Hg0.21mg/kg。主要污染物为Cd,单项污染指数是1.13,单项生态危害系数是50.85,为中等生态危害级,遵义县污染指数最高为1.43,单项生态危害系数为64.35。同时通过污染指数与生态危害系数比较,表明Cd、Hg在构成土壤环境污染的同时,也造成了相应的生态危害。     

沈抚灌区土壤重金属污染健康风险初步评价

采用现场采样及室内测试方法对沈抚灌区农田土壤中Cu、Hg、Ni和Cd等重金属的含量进行了测定分析,利用污染指数法对灌区土壤环境质量进行了评价,并应用美国环保局推荐的健康风险评价模型对灌区土壤重金属通过土壤摄食途径所引起的健康风险作了初步评价。结果表明,灌区土壤中重金属的平均浓度范围分别为Cu：22．1～40．8mg·kg^-1,Hg：0．036-0．310mg·kg^-1,Ni：29．8～44．4mg·kg^-1,Cd：0．145～0．956mg·kg^-1。4种重金属浓度平均值大小为Ni〉Cu〉Cd〉Hg;土壤中Cu、Hg、Ni和Cd所引起的成人和儿童的平均个人风险均低于可接受水平10^-6,且在这两类调查人群中,健康风险大小顺序均为Cd〉Ni〉Hg〉Cu;儿童比成人更易受到土壤重金属的影响,致癌风险是成年的3倍;灌区土壤环境质量环境评价结果显示,灌区土壤重金属污染处于轻微水平。     

重金属铜和锌胁迫下的小麦冠层反射光谱特征

目前关于土壤重金属污染对作物的光谱影响仍然处于探索阶段,受植物种类和环境等因素的影响,植物重金属胁迫机理的诊断仍存在不明确的问题,作物不同生长阶段对不同重金属的耐受程度存在差异。为了探究快速监测作物受重金属污染胁迫状况,采用田间小区试验,利用光谱分析方法研究了土壤重金属不同质量分数铜(0、100、300、600、900 mg/kg)和锌(0、250、500、750、1 000 mg/kg)处理下小麦分蘖期、拔节期和抽穗期冠层光谱特征。结果表明,小麦在分蘖期和拔节期冠层光谱在可见光(350~760 nm)波段内反射率总体随着铜、锌污染浓度的增加而升高,而在近红外(760~900 nm)波段内反射率随铜、锌处理浓度的增加而降低;分蘖期不同浓度铜、锌处理下,小麦冠层光谱出现红边蓝移和红谷蓝移现象;分蘖期铜处理在600、900 mg/kg和拔节期铜处理在900 mg/kg下小麦红边归一化指数值(NDVI705)均低于0.2;分蘖期锌处理在750和1 000 mg/kg下小麦红边归一化指数值(NDVI705)均低于0.2;该试验中引起小麦受到胁迫作用冠层光谱响应的铜临界浓度介于300与600 mg/kg之间,而锌临界浓度介于500与700 mg/kg之间。     

武汉市城郊区集约化露天菜地生产系统硝态氮淋溶迁移规律研究

以武汉市及其周边区域的典型露天菜地为研究对象,对菜地土壤、土壤溶液及菜地附近井水中硝态氮（NO3--N）含量进行了周年监测分析。结果表明:菜地土壤100 cm内各土层NO3--N平均含量为11.2 mg/kg,其中0~20 cm土壤剖面NO3--N含量为21.1 mg/kg;60 cm深度处土壤溶液中NO3--N含量为27.5 mg/L;井水中NO3--N含量为19.6~39.8 mg/L,其含量达到了饮用水安全标准的2~4倍。由此说明:武汉城郊菜地土壤NO3--N淋失量较大,已造成地下水NO3--N污染;且硝酸盐淋失量随着氮肥施用量和水分输入量的增加而增大,同时与种植蔬菜的种类有一定相关关系;由于土壤理化性质不同,土壤硝酸盐含量在正常范围内并且尚能够安全种植作物时,地下水可能已受到严重的污染,这种情况在砂性土壤中表现更为明显。本文的研究为科学评价露天菜地土壤和地下水NO3--N污染提供了科学理论依据。     

晋中盆地土壤重金属分布特征及生态风险

[目的]对晋中盆地土壤重金属分布特征影响及生态风险进行研究和评价,旨在了解该地区土壤污染现状以及为土壤重金属综合治理与防治提供科学依据。[方法]对晋中盆地表层土壤进行采样,测定208个土壤样品中Pb,Cr,Cd,As和Hg这5种重金属的含量,采用单因子污染指数、综合污染指数和潜在生态危害指数对盆地污染进行评价,并利用GIS空间分析技术对污染现状进行分析。[结果]重金属Pb,Cd,Cr,As和Hg的平均含量分别为20.87,0.316,68.226,10.457和0.129mg/kg,分别为山西省土壤背景值的1.42,3.16,1.23,1.15,5.61倍;单因子污染指数结果显示,Hg和Cd为盆地污染的主要贡献因子,Pb,Cr和As对盆地污染的贡献较少;综合污染指数和潜在生态危害指数结果显示,盆地污染程度较为严重,达到中等污染和重度污染的样点占比共达到95%以上;污染空间分析显示,盆地整体污染程度较深,在盆地北部太原地区和南部孝义、介休市存在明显的污染突出地区。[结论]受人类活动影响,晋中盆地土壤重金属污染已较为严重,应引起足够重视。